Cu-63 and Cu-65 are the isotopes of Copper.Cu-63 and Cu-65, are used to study copper metabolism and gastrointestinal diseases. Cu-63 is used for production of medical radioisotope Zn-62 and can also be used for the production of Cu-64 which is used in cancer diagnosis and treatment. Cu-65 has also been proposed as a precursor for the (cyclotron) production of Cu-64.
Solution
Given
The atomic mass of Cu63is 62.93 and relative abundance = 69.2%
The atomic mass of Cu65is 64.93 and relative abundance = 30.8%
Formula
The average atomic mass of an element is calculated by taking the weighted average of the atomic masses of its naturally-occurring isotopes.
avg. atomic mass
=∑ i (isotope i×abundancei)
The atomic masses of these two copper isotopes are 62.93 uand 64.93 u , respectively.
Therefore, relative atomic mass of Cu = (62.93×69.2)+(64.93×30.8) / 100
=63.546
Answer
Therefore, relative atomic mass of Cu =63.546
